Make cookies two days in advance. Prepare and roll out cookie dough following recipe directions. Cut cookies using 3.25 in. cutter from set. Bake and cool cookies. You will need seven cookies per treat.
Outline and fill in cookies two days in advance. Prepare color flow icing following recipe directions. Tint portions pink and red.
Use tip 3 and full-strength pink color flow icing in cut parchment bag to outline cookie. Use thinned pink icing in a cut parchment bag to fill in. Let set 24 hours.
Decorate top cookie for each stack one day in advance. Use tip 3 and full-strength red icing in cut parchment bag to pipe dots, ?X? and ?O?. Let dry 24 hours.
Prepare treat. Place board from Valentine Cookie Treat Kit inside bag. Stack 6 plain cookies in bag. Top stack with ?XO? decorated cookie. Use tie to close bag.